Troubleshooting Hints - Exterior Lights

1. If only one lamp is inoperative, check the wires to connector for opens. Check for an open bulb. Also check for corrosion and/or obvious damage at the connector and terminals.
2. Make sure grounds G115, G116 and G401 are clean and tight.
3. If vehicle is equipped with Daytime Running Lamps (DRL), see Headlamps: Daytime Running Lamps for additional exterior lighting diagnosis.

^ Check for a broken (or partially broken) wire inside of the insulation which could cause system failure but prove "GOOD" in a continuity/voltage check.
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.